From: NeilBrown <neilb@suse.de>
Date: Wed, 2 Mar 2011 23:17:47 +0000 (+1100)
Subject: mkfs: adjust segment size based on device size, and complain if it didn't work.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=9b5b4c1bf1132acd2ffefd5dcf0b531d2f58019a;p=lafs-utils.git

mkfs: adjust segment size based on device size, and complain if it didn't work.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/tools/mkfs.lafs.c b/tools/mkfs.lafs.c
index f3a5157..f51cf0f 100644
--- a/tools/mkfs.lafs.c
+++ b/tools/mkfs.lafs.c
@@ -169,7 +169,8 @@ int is_pow2(long num)
 }
 
 
-void validate_parameters(long *block_bytes, long *segment_bytes, long *stride_bytes, int *width)
+void validate_parameters(long *block_bytes, long *segment_bytes, long *stride_bytes,
+			 int *width, long long device_bytes)
 {
 
 	if (*block_bytes == 0)
@@ -207,6 +208,11 @@ void validate_parameters(long *block_bytes, long *segment_bytes, long *stride_by
 		long blocks = 65536 / *width;
 		blocks *= *width;
 		seg = *block_bytes * blocks;
+		if (seg * 17 > device_bytes) {
+			blocks = device_bytes / 16 / *block_bytes / *width;
+			blocks *= *width;
+			seg = *block_bytes * blocks;
+		}
 		if (*stride_bytes < seg) {
 			seg /= *stride_bytes;
 			seg *= *stride_bytes;
@@ -219,6 +225,16 @@ void validate_parameters(long *block_bytes, long *segment_bytes, long *stride_by
 		*segment_bytes = seg;
 	}
 
+	if (*segment_bytes * 8 > device_bytes) {
+		fprintf(stderr, "lafs.mkfs: segment size too large for device.\n");
+		exit(2);
+	}
+
+	if (*segment_bytes < *block_bytes * 8) {
+		fprintf(stderr, "lafs.mkfs: segment must hold at least 8 blocks.\n");
+		exit(2);
+	}
+
 	if (*segment_bytes % *block_bytes) {
 		fprintf(stderr, "lafs.mkfs: segment size must be a multiple of block size\n");
 		exit(2);
@@ -343,7 +359,8 @@ int main(int argc, char *argv[])
 	dev_fd = open_device(devname, &device_bytes);
 
 	/* Validate parameters */
-	validate_parameters(&block_bytes, &segment_bytes, &stride_bytes, &width);
+	validate_parameters(&block_bytes, &segment_bytes, &stride_bytes, &width,
+			    device_bytes);
 
 	/* Create filesystem handle */
 	lafs = lafs_alloc();